remove some sym_probe_fns methods

remove some sym_probe_fns methods

While looking into the probe API, it seemed to me that there were a
number of methods in sym_probe_fns that were not needed.  This patch
removes them.

Specifically, it seems to me that sym_probe_fns ought to be concerned
with the API for constructing the probes.  Any method relating to some
aspect of an individual probe can be handled via the probe's own
vtable.  That is, the double indirection here doesn't seem useful --
it certainly isn't in fact used, but also I couldn't think of a
potential use.

2013-12-06  Tom Tromey  <tromey@redhat.com>

	* break-catch-throw.c (fetch_probe_arguments): Use
	get_probe_argument_count and evaluate_probe_argument.
	* elfread.c (elf_get_probe_argument_count)
	(elf_can_evaluate_probe_arguments, elf_evaluate_probe_argument)
	(elf_compile_to_ax): Remove.
	(elf_probe_fns): Update.
	* probe.c (get_probe_argument_count, can_evaluate_probe_arguments)
	(evaluate_probe_argument): Call method on probe, not via sym
	functions.
	* stap-probe.c (compute_probe_arg): Use get_probe_argument_count,
	evaluate_probe_argument.
	(compile_probe_arg): Use get_probe_argument_count.  Call method on
	probe, not via sym functions.
	* symfile-debug.c (debug_sym_get_probe_argument_count)
	(debug_can_evaluate_probe_arguments)
	(debug_sym_evaluate_probe_argument, debug_sym_compile_to_ax):
	Remove.
	(debug_sym_probe_fns): Remove.
	* symfile.h (struct sym_probe_fns) <sym_get_probe_argument_count,
	can_evaluate_probe_arguments, sym_evaluate_probe_argument,
	sym_compile_to_ax>: Remove fields.